This invention is directed to a flame retardant molding composition comprising a particular poly(aryl ketone) and a flame retardant additive which is a metal salt of an aromatic sulfonic acid.
Poly(aryl ketone)s are a relatively new class of engineering polymers. Several poly(aryl ketone)s are crystalline. Two of these crystalline poly(aryl ketones) are commercially available and are of the following structure: ##STR1##
These poly(aryl ketone's) exhibit an excellent combination of properties, i.e., excellent thermal and hydrolytic stability, high strength and toughness, excellent wear and abrasion resistance and excellent solvent resistance. Thus articles molded from poly(aryl ketone)s have utility where high performance is required.
However, in many instances, it is required that the articles be flame resistant or flame retardant. Unmodified poly(aryl ketone) exhibits favorable flammability ratings necessary for certain end-use applications. However, under certain stringent conditions of use a poly(aryl ketone) exhibiting increased flame retardance is desirable.
It has now been found that poly(aryl ketone)s are rendered flame retardant by admixing therewith a flame retarding amount of a metal salt of an aromatic sulfonic acid.